Editor steve Turner gives an in-depth overview of what the KR is all about in an upcoming issue of 5.0 Mustang and Super Fords. However, for this Blog report, not only did I just drive the KR around town, I had a chance to put it in the air and really check it out on the bottom side, give it a good workout on the Dynapack Evolution 4000 chassis dyno at Extreme Automotive, and I also got a good ballpark idea of how quickly "The King" can cover the quarter-mile, thanks to a G-Tech Pro RR performance meter.

If you think like we do, and agree that horsepower at the rear wheels should be acknowledged as the "horsepower of record" for a performance Mustang, the "500" part of this Shelby's name is legit. The KR put down one huge blast (509.0 hp/467.7 lb-ft) after we locked it down on the dyno, and supported its ability with subsequent hits of 498 horsepower but with a bit lower torque as the supercharger quickly gave in to heat soak. Also, Ford had the rev limiter locked in at 6,100 rpm on the test KR, so I imagine that 509 might be considerably better with more revs.

It's definitely not hard to literally run out of street with the Shelby GT500 KR. The 'Stang pulls hard and accelerates very, very quickly (.382g on the G-Tech Pro RR), and we calculated its quarter-mile e.t. would be in the mid-11-second range in full street trim. Of course, that's allowing for tires that will surely spin a bit at launch and between shifts. In the perfect world, "The King" is a 10-second Mustang you can buy from a dealer.

Dyno Numbers @ the Source: Mustang50Magazine